Vedran Corluka believes a lack of rotation from manager Harry Redknapp is to blame for Spurs' fall from grace, and the on-loan defender says he expects the club to miss out on next season's Champions League.

Corluka, currently loaned out from Spurs to Bundesliga outfit Bayer Leverkusen, insists Tottenham's fall from early-season title contenders is due to player exhaustion. Redknapp's men have slipped to fifth on the Premier League table with four matches remaining, and Corluka fears his club may have let an opportunity to feature in Europe's top club competition pass by.

"I wouldn't be surprised if they finished sixth," Corluka told BBC Sport. "They didn't rotate enough, they don't have depth on the bench.

"[Redknapp] didn't rotate enough. That's the main problem. I watched almost every Spurs game and they played them all with the same 11, 12, 13 players and that's why the players now are really tired."

Redknapp has called upon 47 players in Spurs' 49 matches across all competitions so far this term, but 10 players have already played in more than 30 games, headed by Kyle Walker with 43 appearances.

At their peak, Spurs moved to within three points of Premier League leaders Manchester City in January. However, defeats at City and Arsenal began a barren run for the club, who have now won three of their last 14 games.

The poor spell has coincided with Redknapp becoming increasingly linked with the vacant England national team position, leading many to speculate that there will be drastic changes at White Hart Lane in the coming summer.

Corluka, who joined Leverkusen in January, insists Spurs are on the brink of an "unsuccessful season".

"Tottenham, for me, had one of the best teams in England and of course it will be an unsuccessful season if they don't go to the Champions League," Corluka said.

"I don't know what the chairman will do if they don't qualify. I know only that it will be an unsuccessful season."

Asked if missing a spot in next season's Champions League place would constitute failure, Corluka said: "Yes, especially because three months before they were in the title race challenging City and [Manchester] United. Now they are three points behind fourth spot. They are fifth and it's going to be really difficult for them."